\\[-1.8ex] Soil Heterogeneity & $-$3.035$^{***}$ & $-$2.142$^{***}$ & $-$2.646$^{***}$ & $-$1.837$^{***}$ & $-$2.822$^{***}$ & $-$1.489$^{**}$ \\ 
  & (0.837) & (0.758) & (0.743) & (0.645) & (0.781) & (0.614) \\ 
\\[-1.8ex] 
Observations & 14,731 & 14,731 & 14,731 & 14,731 & 14,731 & 14,731 \\ 
R$^{2}$ & 0.551 & 0.609 & 0.563 & 0.597 & 0.558 & 0.625 \\ 
